Typically fluid actuators include a piston rod/piston assembly which is mounted in a cylinder (housing) for reciprocal movement therein. The cylinder may be provided with a single end cap to completely close off one end of the cylinder, or the cylinder may be completely enclosed by an end cap at one end and a cylinder head at its other end, if desired. The fluid pressure normally exerts high pressures on the piston, and when the piston reaches the end of its travel, stops suddenly, and reverses the direction of movement, undesirable vibrations tend to occur. Furthermore, such vibrations and sudden stops tend to have adverse effects on the seals on the piston, per se, and on the seals which seal the end cap and cylinder head to the cylinder body. However, when the pistons are subjected to a "buffering" effect at the end of its travel, these adverse effects are eliminated.
One typical solution to the problem has been to provide a tapered, projecting surface on the piston which mates with a tapered recess on the end sealing members of the cylinder so that as the piston nears the end of its travel, the tapered surface on the piston face enters the tapered recess of the end sealing members, and the fluid in the tapered recess tends to retard the entry of the projecting piston surface therein, thus somewhat retarding the piston movement.
It is, therefore, an object of the present invention is to provide a linear braking system for fluid actuators which serves as a means to gradually retard the rate of movement of a reciprocally movable piston/piston rod assembly in a cylinder housing as the piston/piston rod assembly changes its direction of movement.
It is another object of the present invention to provide such a linear brake system which serves as a buffer between end members of the cylinder housing and the piston of the piston/piston rod assembly.
It is a further object of the present invention to provide such a braking system with resilient shock-absorbing means to absorb the shock of the suddenly stopping piston as the piston reverses directions in its reciprocal movement.
It is still a further object of the present invention to provide such a braking system with fluid pressure equalization means to equalize the fluid pressure on one side of the brake body with pressure on the second side of the brake body responsive to the piston reaching the end of its travel.